OpenStack and solid state drives

If you are a service provider or enterprise considering deploying private clouds using OpenStack (an open source alternative to VMware vCloud) then you are in the company of other OpenStack adopters like PayPal and eBay. This article considers the value of SSDs to cloud deployments using OpenStack (not Citrix CloudStack or Eucalyptus).

Block storage & OpenStack: If your public or private cloud is supporting a virtualized environment where you want up to a Terabyte of disk storage to be accessible from within a virtual machine (VM) such that it can be partitioned/formatted/mounted and stays persistent till the user deletes it, then your option for block storage is any storage for which OpenStack Cinder (an OpenStack project for managing storage volumes) supports a block storage driver. Open source block storage options include:

Object storage & OpenStack: On the other hand if your goal is to access multi terabytes of storage and you are willing to access it over a REST API and you want the storage to stay persistent till the user deletes it, then your open source options for object storage include:

Swift – A good choice if you plan to distribute your storage cluster across many data centers. Here objects and files are stored on disk drives spread across numerous servers in the data center. It is the OpenStack software that ensures data integrity & replication of this dispersed data

Ceph – A good choice if you plan to have a single solution to support both block and object level access and want support for thin-provisioning

Gluster – A good choice if you want a single solution to support both block and file level access

Solid state drives (SSD) or spinning disk?

An OpenStack Swift cluster that has high write requirements would benefit from using SSDs to store metadata. Zmanda (a provider of open source backup software) has run benchmarks to prove that SSD based Swift containers outperform HDD based Swift containers especially when the predominant operations are PUT and DELETE. If you are a service provider looking to deploy a cloud based backup/recovery service based on OpenStack Swift and each of your customers is to have a unique container assigned to them, then you stand to benefit from using SSDs over spinning disks.

Turnkey options?

As a service provider if you are looking for an OpenStack cloud-in-a-box to compete with Amazon S3 consider vendors like MorphLabs. They offer turn-key solutions on Dell servers with storage nodes running NexentaStor (commercial implementation of OpenSolaris and ZFS), KVM hypervisor, VMs running Windows or Linux as the guest OS all on a combination of SSDs and HDDs. The use of SSDs allows MorphLabs to claim lower power consumption and price per CPU as compared to “disk heavy” (their term not mine) vBlock (from Cisco & EMC) and FlexPod (from NetApp) systems.

In conclusion if you are planning to deploy clouds based on OpenStack, SSDs offer you some great alternatives to spinning rust (oops disk).